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      <a id="hrtfmove2"></a>
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      <div class="refnamediv">
        <h2>
          <span class="refentrytitle">hrtfmove2</span>
        </h2>
        <p>hrtfmove2 — 
      Generates dynamic 3d binaural audio for headphones using a Woodworth based spherical head model
      with improved low frequency phase accuracy.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp114413328"></a>
        <h2>Description</h2>
        <p>
      This opcode takes a source signal and spatialises it in the 3 dimensional space around a listener
      using head related transfer function (HRTF) based filters.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp114414672"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">aleft, aright <span class="command"><strong>hrtfmove2</strong></span> asrc, kAz, kElev, ifilel, ifiler [,ioverlap, iradius, isr]</pre>
      </div>
      <div class="refsect1">
        <a id="idp114416688"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>ifilel</em></span> -- left HRTF spectral data file
    </p>
        <p>
      <span class="emphasis"><em>ifiler</em></span> -- right HRTF spectral data file
    </p>
        <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
          <table border="0" summary="Note">
            <tr>
              <td rowspan="2" align="center" valign="top" width="25">
                <img alt="[Note]" src="images/note.png" />
              </td>
              <th align="left">Note</th>
            </tr>
            <tr>
              <td align="left" valign="top">
                <p>
        Spectral datafiles (based on the MIT HRTF database) are available in 3 different sampling rates: 44.1, 48 and 96 khz and are labelled accordingly. Input and processing <span class="emphasis"><em>sr</em></span> should match datafile <span class="emphasis"><em>sr</em></span>. Files should be in the current directory or the SADIR (see <a class="link" href="CommandEnvironment.html" title="Csound Environment Variables"><em class="citetitle">Environment Variables</em></a>).
      </p>
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          <table border="0" summary="Note">
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                <img alt="[Note]" src="images/note.png" />
              </td>
              <th align="left">Note</th>
            </tr>
            <tr>
              <td align="left" valign="top">
                <p>
       HRTF Data files for use with 
      <a class="link" href="hrtfmove.html" title="hrtfmove"><em class="citetitle">hrtfmove</em></a>,
      <a class="link" href="hrtfmove2.html" title="hrtfmove2"><em class="citetitle">hrtfmove2</em></a>,
      <a class="link" href="hrtfstat.html" title="hrtfstat"><em class="citetitle">hrtfstat</em></a>,
      <a class="link" href="hrtfearly.html" title="hrtfearly"><em class="citetitle">hrtfearly</em></a>,
      <a class="link" href="hrtfreverb.html" title="hrtfreverb"><em class="citetitle">hrtfreverb</em></a>
       were updated for Csound 5.15 and later (the code was updated and is more efficient). Old datafiles are now deprecated.
      </p>
              </td>
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        </div>
        <p>
      <span class="emphasis"><em>ioverlap</em></span> -- optional, number of overlaps for STFT processing (default 4). See STFT section of manual.
    </p>
        <p>
      <span class="emphasis"><em>iradius</em></span> --  optional, head radius used for phase spectra calculation in centimeters (default 9.0)
    </p>
        <p>
      <span class="emphasis"><em>isr</em></span> - optional, default 44.1kHz, legal values: 44100, 48000 and 96000.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp114430352"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>asrc</em></span> -- Input/source signal.
    </p>
        <p>
      <span class="emphasis"><em>kAz</em></span> -- azimuth value in degrees. Positive values represent position on the right, negative values are positions on the left.
    </p>
        <p>
      <span class="emphasis"><em>kElev</em></span> -- elevation value in degrees. Positive values represent position above horizontal, negative values are positions below horizontal (min -40).
    </p>
        <p>
      Artifact-free user-defined trajectories are made possible using an interpolation algorithm based on spectral
      magnitude interpolation and a derived phase spectrum based on the Woodworth spherical head model.
      Accuracy is increased for the data set provided by extracting and applying a frequency dependent scaling factor
      to the phase spectra, leading to a more precise low frequency interaural time difference.
      Users can control head radius for the phase derivation, allowing a crude level of individualisation.
      The dynamic source version of the opcode uses a Short Time Fourier Transform algorithm to avoid artefacts
      caused by derived phase spectra changes. STFT processing means this opcode is more computationally intensive
      than <a class="link" href="hrtfmove.html" title="hrtfmove"><em class="citetitle">hrtfmove</em></a> using phase truncation, but phase is constantly updated by <span class="emphasis"><em>hrtfmove2</em></span>.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp114436512"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the hrtfmove2 opcode. It uses the file <a class="ulink" href="examples/hrtfmove2.csd" target="_top"><em class="citetitle">hrtfmove2.csd</em></a>.
    </p>
        <div class="example">
          <a id="idp114438496"></a>
          <p class="title">
            <strong>Example 371. Example of the htrfmove2 opcode.</strong>
          </p>
          <div class="example-contents">
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select flags here</span>
<span class="comment">; realtime audio out </span>
 -o dac 
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o hrtf.wav</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 2

gasrc <span class="opc">init</span> 0

<span class="oblock">instr</span> 1		<span class="comment">;a plucked string</span>

  kamp <span class="op">=</span> p4
  kcps <span class="op">=</span> <span class="opc">cpspch</span>(p5)
  icps <span class="op">=</span> <span class="opc">cpspch</span>(p5)

  a1 <span class="opc">pluck</span> kamp, kcps, icps, 0, 1

  gasrc <span class="op">=</span> a1

<span class="oblock">endin</span>

<span class="oblock">instr</span> 10	<span class="comment">;uses output from instr1 as source</span>

 kaz	<span class="opc">linseg</span> 0, p3, 720		<span class="comment">;2 full rotations</span>

 aleft,aright <span class="opc">hrtfmove2</span> gasrc, kaz,0, "hrtf<span class="op">-</span>44100<span class="op">-</span>left.dat","hrtf<span class="op">-</span>44100<span class="op">-</span>right.dat"

 <span class="opc">outs</span>	aleft, aright

<span class="oblock">endin</span>

<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>

<span class="comment">; Play Instrument 1: a simple arpeggio</span>
<span class="stamnt">i</span>1 0 .2 15000 8.00 
<span class="stamnt">i</span>1 + .2 15000 8.04
<span class="stamnt">i</span>1 + .2 15000 8.07
<span class="stamnt">i</span>1 + .2 15000 8.11
<span class="stamnt">i</span>1 + .2 15000 9.02
<span class="stamnt">i</span>1 + 1.5 15000 8.11
<span class="stamnt">i</span>1 + 1.5 15000 8.07
<span class="stamnt">i</span>1 + 1.5 15000 8.04
<span class="stamnt">i</span>1 + 1.5 15000 8.00
<span class="stamnt">i</span>1 + 1.5 15000 7.09
<span class="stamnt">i</span>1 + 1.5 15000 8.00

<span class="comment">; Play Instrument 10 for 10 seconds.</span>
<span class="stamnt">i</span>10 0 10

<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <br class="example-break" />
      </div>
      <div class="refsect1">
        <a id="idp114440288"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="hrtfmove.html" title="hrtfmove"><em class="citetitle">hrtfmove</em></a>,
      <a class="link" href="hrtfstat.html" title="hrtfstat"><em class="citetitle">hrtfstat</em></a>,
      <a class="link" href="hrtfer.html" title="hrtfer"><em class="citetitle">hrtfer</em></a>.
    </p>
        <p> More information on this opcode: <a class="ulink" href="http://www.csoundjournal.com/issue9/newHRTFOpcodes.html" target="_top"><em class="citetitle">http://www.csoundjournal.com/issue9/newHRTFOpcodes.html</em></a>  , written by Brian Carty </p>
      </div>
      <div class="refsect1">
        <a id="idp114445648"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Brian Carty</td>
          </tr>
          <tr>
            <td>Maynooth</td>
          </tr>
          <tr>
            <td>2008</td>
          </tr>
        </table>
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    </p>
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